Composition containing a non-photocatalytic metal oxide and tocopherol, its use in the cosmetics and/or dermatological field and processes employing it

ABSTRACT

Cosmetic and/or dermatological compositions containing a non-photocatalytic metal oxide and tocopherol and, optionally, a metal-inactivating complexing agent are effective for inhibiting the light-induced peroxidation of lipids, and in particular lipids of sebaceous origin such as squalene.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to compositions which contain anon-photocatalytic metal oxide and tocopherol, which are useful, inparticular, in the cosmetics, pharmaceutical, veterinary andagri-foodstuffs fields. The present compositions make it possible, inparticular, to inhibit the light-induced peroxidation of unsaturatedlipids, and more especially lipids of sebaceous origin (sebum).

The compositions of the present invention may take the form of a creamwhich can be applied either to the face or to the scalp and hair, aswell as to the human body. The present compositions can also serve as abase for a lipstick. More specifically, the present invention relates tocompositions which contain a zinc oxide and tocopherol actingsynergistically.

The present invention also relates to a method of combating and/orpreventing skin irritations, skin inflammations, acne andimmunosuppression, as well as to a method for combating and/orpreventing the signs of aging. Such skin phenomena are, in particular,induced by solar radiation. The present invention further relates to aprocess for preserving products containing a photooxidizable lipid.

2. Discussion of the Background

The lipids occurring at the surface of the skin, scalp and hair areknown to be continuously subjected to damaging external agents, inparticular air, atmospheric pollutants and visible and most especiallyultraviolet (UV) radiation.

These lipids are those which form part of the constituents of the skinor hair, as well as those which are secreted by the skin including thescalp, and/or those which are deposited on the skin or hair whenproducts containing lipids are applied to the skin or hair.

The lipids most exposed to damaging external agents are those containedin the fatty secretions of the skin such as sebum, which is rich insqualene. The presence of six double bonds in squalene makes squalenesensitive to oxidation. Thus, on prolonged exposure to UV, squalene isphotoperoxidized to give squalene peroxides.

This high production of squalene peroxides causes, in particular, aseries of sequential degradations especially in and on the skin, givingrise to many skin disorders. Thus, these squalene peroxides participatein:

(i) the pathogenesis of acne, as described by Saint L eger et al (seeBritish Journal of Dermatology, vol. 114, pp. 535-542 (1986) who pointout that squalene peroxides are comedogenic;

(ii) premature skin aging, as described by Keiko OH Sawa et al (see TheJournal of Toxicology Sciences, vol. 19, pp. 151-159 (1984)) who discussthe consequences of sun-induced skin burns;

(iii) irritation phenomena, as reported by Takayoshi Tanaka et al (seeJ. Clin. Biochem. Nutr., vol. 1, pp. 201-207 (1986)) who draw attentionto the damage caused, in particular, by the repeated use of someshampoos;

(iv) the production of malodorous volatile products (aldehydes, ketones,acids, and the like); and

(v) immunosuppression of biochemical messengers of the biologicaleffects of UV irradiation of the skin, as described by M. Picardo et al.(see Photodermatol. Photoimmunol. Photomed., vol. 3, pp. 105-110(1991)).

In order to limit the peroxidation of unsaturated lipids, it is known toapply to the skin photoprotective compositions containing at least oneanti-free-radical agent and at least one screening agent.

This is the case, for example, with the complex composition described inFR-A 2666226 relating to a cream for combating photon intolerance, andwhich contains alpha-tocopherol among other anti-free-radicalconstituents and titanium oxide among several physical and chemicalscreening agents present in the composition. This composition has thedrawback of affording little protection against ultraviolet radiationand of being unsuitable for the cosmetics and dermatological fields onaccount of problems associated with the "photocatalytic" activity oftitanium oxide, as explained below.

In effect, the inventors have found, according to the headspace method,that titanium oxide, under ultraviolet exposure or after a few hours at37° C., catalyses the production of peroxide radicals from the lipidconstituents contained in cosmetic compositions. On application of thesecompositions to the skin, this gives rise to harmful effects such asinflammation. For a description of this method, reference may be madeespecially to the publications of Q. L. N'guyen et al, Symposium ofAFECG-SFC, Bordeaux, May 1984, pp. 358-359, "Evaluation de l'oxydationald ehydique dans les produits cosm etiques" ["Evaluation of aldehydeoxidation in cosmetic products"]; and of K. Warner et al, "Pentaneformation and rancidity in vegetable oils", Journal of Food Science,vol. 39, pp. 761-765 (1974).

For this reason, in order to overcome the drawbacks associated with theuse of titanium oxide, surface treatments of titanium oxide have beensuggested, for example in WO-A-90/09777. However, such treatments do notenable the photocatalytic activity of titanium oxide to be decreasedsufficiently, and use of the treated titanium can also cause skin damageon exposure to UV.

The beneficial properties of zinc oxide for the skin are, moreover,known. In particular, zinc oxide retains greases and moisture, absorbsUV, possesses good covering power and is, in addition, soothing (see,for example, the publication of L. D. Grady appearing in The Journal ofthe Society of Cosmetic Chemistry: 1947, July, volume 1). Thus, zincoxide has been incorporated in cosmetic compositions such as facepowders (see the above publication of L. D. Grady).

More recently, the company NIVEA has marketed a composition in mask formcalled "Masque 3 minutes Hydro-purifiant" which contains, among otheringredients, zinc oxide for its astringent properties, tocopherolacetate for its activity in cell regeneration and kaolin to absorb theexcess sebum. This composition is not designed to inhibit thephotoperoxidation of lipids, and in particular squalene, and is notcapable of inhibiting this photoperoxidation.

An anti-sun cream based on zinc oxide and about ten other constituentsincluding an antioxidant is disclosed in GB-A-2,184,356. However, theuse of a tocopherol as an antioxidant for the purpose of combating thephotoperoxidation of unsaturated lipids, in particular those ofsebaceous origin such as squalene is not taught.

Moreover, it is known from EP-A-579,078 to combine zinc oxide andtocopherol, but this document neither teaches nor suggests theinhibition of the photoperoxidation of unsaturated lipids by thiscombination, particularly since, in the examples, tocopherol is used inits acetate form, a form which is not capable of inhibiting thisphotoperoxidation.

Thus, the compositions known to date confer insufficient or even zeroprotection of the skin against the peroxidation of lipids of and on theskin.

Accordingly, there remains a need for compositions capable of inhibitingthe active forms of oxygen, and in particular displaying effectiveactivity in combating lipid peroxidation, in particular in combatingsqualene peroxidation, on exposure to ultraviolet light and/or to otheroxidizing factors, and which is well tolerated by the skin and/or hair.

In the context of the present invention, the term "active forms ofoxygen" is understood to mean forms of oxygen, free-radical orotherwise, such as, in particular, ROOH (R representing, in particular,the hydrocarbon chain of an unsaturated lipid), OH.sup.•, ROO.sup.•, O₂H.sup.•, ¹ O₂ and more especially ROOH where R is the hydrocarbon chainof squalene.

SUMMARY OF THE INVENTION

Accordingly, it is one object of the present invention to provide novelcompositions useful for combating the peroxidation of unsaturatedlipids.

It is another object of the present invention to provide novelcompositions useful for combating the peroxidation of squalene.

It is another object of the present invention to provide novelcompositions useful for combating the peroxidation of unsaturated lipidsresulting from exposure to ultraviolet light and/or other oxidizingfactors.

It is another objection of the present invention to provide novelcompositions useful for combating the peroxidation of unsaturated lipidswhich are well tolerated by the skin and/or hair.

It is another object of the present invention to provide novelcompositions useful for stabilizing compositions which contain anunsaturated lipid against peroxidation.

It is another object of the present invention to provide novel methodsfor combating the peroxidation of unsaturated lipids.

It is another object of the present invention to provide novel methodsfor combating the peroxidation of squalene.

It is another object of the present invention to provide novel methodsfor combating the peroxidation of unsaturated lipids resulting fromexposure to ultraviolet light and/or other oxidizing factors.

It is another object of the present invention to provide novel methodsfor combating the peroxidation of unsaturated lipids which are welltolerated by the skin and/or hair.

It is another object of the present invention to provide novel methodsfor stabilizing compositions which contain an unsaturated lipid againstperoxidation.

These and other objects, which will become apparent during the followingdetailed description, have been achieved by the inventors' discoverythat compositions comprising at least one non-photocatalytic metal oxideand at least one tocopherol are effective for inhibiting thephotoperoxidation of unsaturated lipids.

Thus, the inventors have found that the efficacy of such compositionsdepends on the choice of antioxidant to be combined with thenon-photocatalytic metal oxide.

Accordingly, one embodiment of the present invention is a method forinhibiting the photoperoxidation of unsaturated lipids by applying acomposition comprising at least one non-photocatalytic metal oxide andat least one tocopherol, in a cosmetic and/or dermatologicalcomposition.

A further embodiment of the present invention is a method for combatingand/or preventing the light-induced signs of aging by applying to theskin a composition comprising at least one non-photocatalytic metaloxide and at least one tocopherol.

As a result of the fact that the compositions of the present inventioninstantaneously block the initiation of peroxidation reactions in thepresence of radiation, the present compositions are especially usefulfor combating irritation or even inflammation of the skin,immunosuppression and acne which are induced by light.

Thus, a further embodiment of the present invention is a method fordermatological treatment for combating and/or preventing irritation,inflammation, immunosuppression and/or acne which are induced by thephotoperoxidation, in particular, of squalene by applying the presentcomposition to the skin.

According to a preferred embodiment of the present invention, thepresent composition further comprises at least one metal-inactivatingcomplexing agent enabling the metals possibly present in thecomposition, and in particular those in the water used, to be complexed,and these metals hence to be rendered inactive.

Hence another embodiment of the present invention is a method forinhibiting the photoperoxidation of unsaturated lipids, by contactingthe lipid with a composition which comprises at least one tocopherol, atleast one non-photocatalytic metal oxide and at least onemetal-inactivating complexing agent.

BRIEF DESCRIPTION OF THE DRAWING

A more complete appreciation of the invention and many of the attendantadvantages thereof will be readily obtained as the same become betterunderstood by reference to the following detailed description whenconsidered in connection with the accompanying drawing, wherein:

FIGURE 1 is a graph comparing the efficacies of tocopherol andtocopherol acetate with respect to the peroxidation of sebum in an exvivo test at an irridation of 5 Joules UVA/cm² : □, tocopherol acetate;and ▪, tocopherol.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the context of the present invention, the term "tocopherol" isunderstood to mean α-tocopherol, β-tocopherol, γ-tocopherol and/orδ-tocopherol.

Furthermore, according to the present invention, one or more tocopherolsand one or more metal oxides may be used.

The term "metal-inactivating complexing agent" is understood to mean anagent which prevents the formation of hydroxyl radicals, OH.sup.•, as aresult of a strong uptake of the metals present in the composition, whenthese agents are subjected to radiation, in particular UV radiation. Inparticular, these agents effect the complexing under UV of the metalscontained in water, and especially iron.

In particular, the inventors have observed that butylated hydroxytoluene(BHT) and superoxide dismutase (SOD), which are well-known antioxidants,have only a weak effect in combating lipid peroxidation, and cannothence be usefully combined with a non-photocatalytic metal oxide inorder to inhibit the peroxidation of unsaturated lipids.

According to the invention, the composition runs no risk of causingintolerance, and may be used with complete safety, in particular in thecosmetics, dermatological or even veterinary fields.

In addition, the present compositions provide effective protectionagainst any oxidative attack without having recourse to other screeningagents, in particular those of a chemical nature. Thus, the compositionsof the present invention possess a more natural aspect, sought by theconsumer, than the existing compositions in the cosmetics field, and aremuch simpler to produce than such compositions, and hence lessexpensive.

The compositions of the present invention can exist in variouspharmaceutical dosage forms, and especially in the form of oil-in-wateror water-in-oil emulsions, solutions, gels or vesicular dispersions. Thepresent compositions can be a skincare cream, a shampoo, a lotion or aserum.

The non-photocatalytic metal oxide/tocopherol weight ratio in thecomposition of the present invention is typically from 100:1 to 1:4, andpreferably from 10:1 to 2:1.

According to the invention, the non-photocatalytic metal oxide which isusable in the composition is preferably a bivalent metal oxide. Thismetal oxide may be coated or otherwise. As a non-photocatalytic bivalentmetal oxide, zinc oxides, treated titanium oxides, selenium oxides,cerium oxides, magnesium oxides and zirconium oxides may be used.Preferably, zinc oxides are used.

Furthermore, the zinc oxide is present in the composition of the presentinvention preferably in the form of spherical particles. Advantageously,it should not contain traces of noxious heavy metals such as cadmium,lead, and the like. The average diameter of these nanoparticles ischosen, for example, to be from 1 nm to 500 nm, and preferably about 100nm.

As zinc oxide, the one described in WO-A-92/13517 and marketed by thecompany Sunsmart under the name Z-cote may be used. This type of zincoxide is transparent, which is an advantage in the cosmetics field froman aesthetic standpoint, the common pulverulent screening agentsgenerally being opaque.

The metal oxide is generally present in the present composition in anamount of 0.1% to 5% by weight, preferably 0.5% to 2% by weight, basedon the total weight of the composition.

According to the present invention, the tocopherol is present in thecomposition in the "free state", that is to say without any additionalgroups and in particular without an ester-forming group.

Preferably, the tocopherol used is a mixture of natural tocopherols,especially α-tocopherol, β-tocopherol, γ-tocopherol and δ-tocopherol;this mixture may be used, in particular, in an oil chosen fromvegetable, mineral and silicone oils, and preferably vegetable oils.

As a mixture of natural tocopherols which is usable in the presentinvention, the one dissolved at a concentration of 50% in soya bean oil,sold by the company BIZEN under the name D mixed tocopherola, may bementioned. The D-α-tocopherol sold by the company HENKEL under the nameCopherol F1300 or alternatively those described in U.S. Pat. No.4,144,325 may also be used.

The tocopherol (or mixture) may be present (active substance) in thecomposition of the present invention in an amount of 0.0005% to 10% byweight, preferably in an amount of at least 0.02% and up to 6% byweight, based on the total weight of the composition.

The metal-inactivating complexing agent which is usable in thecomposition of the present invention is, for example, a phosphonic acidderivative, and is chosen especially from3-ethylenediaminetetra(methylenephosphonic acid),diethylenetriaminepenta(methylenephosphonic acid) and their sodiumsalts. Preferably, the complexing agent isdiethylenetriaminepenta(methylenephosphonic acid) pentasodium salt.

As other complexing agents neutralizing the action of metals,diethylenetriaminepentaacetic acid, sold, for example, by the companySIGMA, may also be used.

Complexing agents such as ethylenediaminetetraacetic acid (EDTA), whichis an iron chelator, possess a prooxidant effect under UV radiation, andhence cannot be used alone in the composition of the present inventiondesigned to have an antioxidant effect. However, it is possible to usethis type of agent in combination especially with a phosphonic acidderivative.

When the metal-inactivating complexing agent is present, it is presentin an amount of from 0.005% to 0.5% by weight, preferably 0.005 to 0.3%by weight, based on the total weight of the composition.

Thus, a preferred composition according to the present invention forinhibiting the active forms of oxygen comprises, by weight, based on thetotal weight of the composition:

(a) from 0.05% to 2% of a mixture of natural tocopherols;

(b) from 0.5% to 5% of zinc oxide; and

(c) from 0.05% to 0.1% of diethylenetriaminepenta(methylenephosphonicacid) sodium salt.

The compositions of the present invention can, moreover, containadjuvants, used alone or mixed, and especially those chosen fromsurfactants (emulsifier or coemulsifier) of the nonionic, anionic,cationic or amphoteric type, treatment agents, active agents,thickeners, suspending agents, colorants, perfumes, fillers,neutralizing agents, excipients (oils/water) and preservatives.

The adjuvants mentioned may be incorporated in the usual amountscommonly accepted, avoiding as far as possible adjuvants liable torelease metals which catalyze oxidation. The adjuvants may be lipophilicor hydrophilic.

In the composition according to the present invention, the polymer basedon polyacrylamide, C₁₃ -C₁₄ isoparaffin and laureth-7 (according to theCTFA nomenclature) may advantageously be used as thickening agent.

The composition of the present invention is intended more especially forinhibiting the UV radiation-induced peroxidation of the unsaturatedlipids of sebum, such as squalene.

Surprisingly, the inventors have discovered that the composition of thepresent invention very effectively inhibits the UV-induced formation ofsqualene peroxides as a result of a surprising synergistic effectbetween its two constituents, the non-photocatalytic metal oxide andtocopherol. This effect was demonstrated in ex vivo tests which aredescribed in detail below.

In the particular case of the treatment of acne, a specific anti-acne,an antiseborrhoeic and/or an antibacterial agent, and especiallypiroctone olamine, sold under the name Octopirox by the company HOECHST,may also be advantageously incorporated in the composition of thepresent invention.

In another embodiment, the present invention provides a method forcombating the signs of ageing which are induced by the photoperoxidationof squalene, by topical application of a composition according to theinvention to the skin and/or scalp and/or hair.

By virtue of its beneficial properties, the composition of the presentinvention is suitable for the protection of any type of skin, and moreespecially greasy skins and so-called sensitive skins. It may also serveto protect the lips against chapping.

In the present method of combating the signs of ageing, the presentcomposition is applied to the skin in an amount such that 0.002 to 0.1mg/cm², preferably 0.01 to 0.04 mg/cm², of the non-photocatalytic metaloxide is applied to the skin, and 0.00001 to 0.2 mg/cm², preferably0.0004 to 0.12 mg/cm², of the tocopherol is applied to the skin, and, ifpresent in the composition, 0.0001 to 0.01 mg/cm², preferably 0.0001 to0.006 mg/cm², of the metal-inactivating complexing agent is applied tothe skin. The present composition may be applied one or more times dailyor less frequently. In a preferred embodiment, the present compositionis applied to the skin within one or two hours prior to exposure tointense radiation such as sunbathing.

On the same basis as the topical treatment, the composition of theinvention may be used for preserving products containing aphotooxidizable lipid. Thus, a further embodiment of the presentinvention is a process for preserving cosmetics, agri-foodstuffs and/orpharmaceutical products containing at least one photooxidizable lipid,which comprises incorporating a composition according to the presentinvention in the such products.

Other features of the present invention will become apparent in thecourse of the following descriptions of exemplary embodiments which aregiven for illustration of the invention and are not intended to belimiting thereof.

EXAMPLES

In the following examples and reference examples, the percentages aregiven by weight. The term "q.s. 100%" means that that ingredient ispresent in an amount sufficient to make the sum of amounts for allingredients equal to 100%.

EXAMPLE 1

Anti-acne cream for greasy skins

    ______________________________________                                        Tocopherol and soya bean oil (50:50)                                                                    0.5%                                                Glyceryl stearate         0.3%                                                FC and C Red No. 4 (colorant)                                                                           0.0001%                                             Acid Yellow 3 (colorant)  0.0005%                                             Methyl para-hydroxybenzoate                                                                             2%                                                  (preservative)                                                                Hexamidine diisethionate (preservative)                                                                 0.03%                                               Piroctone olamine (anti-acne)                                                                           0.2%                                                Perfume                   0.3%                                                Triethanolamine (neutralizing agent)                                                                    0.002%                                              Ethylenediamnetetra(methylenephosphonic                                                                 0.01%                                               acid) pentasodium salt                                                        Zinc oxide                2%                                                  Xanthan gum (thickener)   0.3%                                                Polyacrylamide/C.sub.13 -C.sub.14                                                                       2%                                                  isoparaffin/laureth-7 (thickener)                                             Cyclomethicone (oil)      6%                                                  Glycerol (active agent)   3%                                                  Propylene glycol (active agent)                                                                         6%                                                  Cetyl alcohol (coemulsifier)                                                                            1.0%                                                PEG-20 stearate (emulsifier)                                                                            1.7%                                                D-Panthenol (active agent)                                                                              1%                                                  Water q.s.                100%                                                ______________________________________                                    

The cream thus prepared has a pH value of 6 to 7 and protects the skin,and especially the lipid constituents at the surface of the skin,against the adverse effects of UV. It may be applied every morning.

REFERENCE EXAMPLE 1

A cream is prepared having the same composition as that of Example 1except for the zinc oxide.

REFERENCE EXAMPLE 2

A cream is prepared having the same composition as that of Example 1except for the tocopherol.

REFERENCE EXAMPLE 3

A cream is prepared having the same composition as that of Example 1except for the zinc oxide and the tocopherol (placebo).

To measure the respective efficacy of the composition of the invention(Ex. 1) , as well as that of the compositions of the above referenceexamples, an ex vivo test is performed according to the followingprotocol:

A sebum sample is taken from the forehead of volunteers using four 17.4cm² hydrophilic filter papers. The composition according to Example 1 isthen applied to one of these four filter papers in the proportion of 4mg/cm². Approximately 4 mg/cm² of the compositions of Reference Example1, of Reference Example 2, and of the placebo (without zinc oxide ortocopherol) are then applied to the second, third, and fourth filters,respectively. The samples were all subjected to a dose of UVA of 5joules per cm² for 50 min. The UV source used has a power of 2 mW/cm².

The results obtained are recorded in Table I, which shows the values forpercentage inhibition of photoperoxidation obtained for Example 1 andthe Reference Examples, respectively.

                  TABLE I                                                         ______________________________________                                        Ex. 1     Reference   Reference Reference                                     (Invention)                                                                             Ex. 1       Ex. 2     Ex. 3                                         ______________________________________                                        65%       9%          18%       0%                                            ______________________________________                                    

Hence it is seen from Table I that the level of inhibition achieved withthe composition of the present invention (65%) is markedly higher thanthe sum of the levels of inhibition (9%+18%) obtained using tocopheroland zinc oxide taken separately. It follows that tocopherol unexpectedlyincreases the efficacy of zinc oxide, and vice versa.

EXAMPLE 2

Non-irritant shampoo

    ______________________________________                                        Zinc oxide                0.5%                                                Carbomer (*)              0.2%                                                Triethanolamine (neutralizing agent)                                                                    0.2%                                                MEA-laureth sulfate (**) (active                                                                        10%                                                 substance)                                                                    Coco-betaine (**)          2%                                                 Cocoamide DEA (**)         3%                                                 Tocopherol and soya bean oil (50:50)                                                                    0.2%                                                Perfume                   q.s.                                                Water q.s.                100%                                                ______________________________________                                         (*) Carbopol 980 sold by the company Goodrich                                 (**) According to the CTFA nomenclature                                  

EXAMPLE 3

Protective gel for sensitive skins

    ______________________________________                                        Tocopherol and soya bean oil                                                                            0.5%                                                FD and C Red No. 4        0.0001%                                             Acid Yellow 3             0.0005%                                             Methyl para-hydroxybenzoate                                                                             0.18%                                               Hexamidine diisethionate  0.03%                                               Perfume                   0.3%                                                Triethanolamine           0.002%                                              Ethylenediaminetetra(methylenephosphonic                                                                0.01%                                               acid) pentasodium salt                                                        Zinc oxide                2%                                                  Xanthan gum               0.3%                                                Polyacrylamide/C.sub.13 -C.sub.14                                                                       2%                                                  isoparaffin/laureth-7                                                         Cyclomethicone            6%                                                  Glycerol                  3%                                                  Propylene glycol          6%                                                  D-Panthenol               1%                                                  Water q.s.                100%                                                ______________________________________                                    

Ex Vivo Comparison

An ex vivo test is presented below showing the need to use a freetocopherol and not a tocopherol derivative such as tocopherol acetate.FIGURE 1 shows the curves for inhibition of the peroxidation of sebum.

The ordinate axis corresponds to the percentage inhibition ofperoxidation, and the abscissa axis corresponds to the tocopherol ortocopherol acetate concentration. The curve (a) corresponds totocopherol and the curve (b) to tocopherol acetate. On comparing thesetwo curves, it is clearly apparent that only tocopherol enables a goodinhibition of the peroxidation of sebum to be obtained.

The test protocol was as follows:

for each curve (a) and (b), a sebum sample was taken from the foreheadof an individual using two hydrophilic filters;

in each case, a placebo was applied to one filter and the creamcontaining the active agent to the other filter, that is to saytocopherol in one case and tocopherol acetate in the other case, theactive agent being present in the cream at a specified concentration,and the placebo and the cream being applied at a concentration of 3mg/cm² ;

the filters were then subjected to an irradiation of 5 joules UVA percm² ;

the level of squalene peroxides on the filters was then determined byreverse-phase chromatography and chemiluminescence;

the results obtained are shown in FIGURE 1.

The creams and the placebo have the compositions shown in Table II

                  TABLE II                                                        ______________________________________                                                              Cream     Cream                                                               containing                                                                              containing                                    Composition                                                                              Placebo    0.05%     0.1%                                          ______________________________________                                        Oily phase 35%        34.95%    34.9%                                         Active agent                                                                              0%        0.05%     0.1%                                          Water      65%        65%       65%                                           ______________________________________                                    

The oily phase has the following percentage composition:

    ______________________________________                                        Cetyl alcohol       14%                                                       Glyceryl stearate   9%                                                        PEG-50 stearate     9%                                                        Caprylic/capric triglycerides                                                                     9%                                                        Mineral oil q.s.    100%                                                      ______________________________________                                    

This application is based on French Patent Application No. 94-02882,filed on Mar. 11, 1994, which is incorporated herein by reference in itsentirety.

Obviously, numerous modifications and variations of the presentinvention are possible in light of the above teachings. It is thereforeto be understood that, within the scope of the appended claims, theinvention may be practiced otherwise than as specifically describedherein.

What is claimed as new and desired to be secured by Letters Patent ofthe United States is:
 1. A composition for inhibiting thephotoperoxidation of unsaturated lipids, which comprises;1) 0.02-6% byweight of at least one tocopherol selected from the group consisting ofα-tocopherol, β-tocopherol, γ-tocopherol, δ-tocopherol and a mixturethereof; 2) 0.1-5% by weight of zinc oxide or dioxide; and 3) 0.005-0.3%by weight of a metal-inactivating complexing agent selected from thegroup consisting of ethylenediaminetetra(methylenephosphonic acid),diethylenetriaminepenta(methylenephosphonic acid), sodium salts thereof,and a mixture thereof.
 2. The composition of claim 1, wherein saidmetal-inactivating complexing agent is present in an amount of 0.005% to0.1% by weight, based on the total weight of said composition.
 3. Thecomposition of claim 1, wherein said zinc oxide or titanium dioxide andsaid tocopherol are present in a weight ratio of from 100:1 to 1:4. 4.The composition of claim 3, wherein said weight ratio is from 10:1 to2:1.
 5. The composition of claim 1, wherein said zinc oxide is in theform of spherical particles with an average diameter from 1 to 500 nm.6. The composition of claim 1, further comprising an adjuvant selectedfrom the group consisting of nonionic surfactants, anionic surfactants,cationic surfactants, amphoteric surfactants, treatment agents, activeagents, thickeners, suspending agents, colorants, perfumes, fillers,neutralizing agents, excipients, preservatives, and mixtures thereof. 7.The composition of claim 1, further comprising a cosmetically acceptablemedium, a dermatologically acceptable medium or both.